They are a good wheeze for some people and organisations making them a load of money in subsidies, that we pay for, yet providing 'them' with a good income. Then we pay for the electricity at a premium price because of the subsidies. Neat scam. If we had made up a scam like that we would be behind bars.
We'd like to bet that they won't age as well as Victorian engineering either. They'll all have fallen down by the time the next two hundred years are up.